test.c

支持Linux 内核2.4版本的字符设备模块示例

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <error.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>

int main(int argc, char **argp)
{
    int fd = open("/dev/my_driver", O_CREAT|O_RDWR, 0664);
    if(fd < 0)
    {
        printf("open \"/dev/my_driver\" failure.\n");
        return EXIT_FAILURE;
    }
    
    printf("fd:%d\n",fd);

    char *pWriteData = "abcdefghijklmnopqrstuvwxyz123456789";
    char szBuffer[1024] = {0};
    int iReadBytes = 0;
    int iWriteBytes = write(fd, pWriteData, strlen(pWriteData));
    if(iWriteBytes == strlen(pWriteData))
    {
        printf("write data \"%s\" to \"/dev/my_driver\" success.\n");
        iReadBytes = read(fd, szBuffer, strlen(pWriteData));
        if(iReadBytes > 0)
        {
            printf("read data from \"/dev/my_driver\" success,data:%s.\n",szBuffer);
        }
        else
        {
            printf("read data from \"/dev/my_driver\" failure.\n");
        }
    }
    else
    {
        printf("write data to \"/dev/my_driver\" failure, %d.\n",iWriteBytes);
    }
    
    close(fd);
    fd = -1;
    return EXIT_SUCCESS;
}